Technical Field
The disclosure relates to a touch device, and in particular it relates to a contact via in a touch device.
Description of the Related Art
Conventional touch devices usually include sensing electrodes and traces electrically connected thereto on a substrate. The traces can be electrically connected to a bonding pad set, and the bonding pad set can be further electrically connected to an external circuit (i. e. flexible circuit board). As such, the current or signals can be transferred from the external circuit to the sensing electrodes through the bonding pad set and the traces, thereby driving the touch device.
In the conventional art, the described elements are usually electrically connected through contact holes. However, residual etchant used in the formation of the contact vias in an etching process usually remains in the corners of the bottom of the contact vias. This residual etchant may cause over-etching problems. In addition, if the corners of the top of the contact vias have an overly small angle (e.g. less than or equal to 90 degrees), it will cause point-discharge problems. Accordingly, a novel contact via is called for to solve the problems described above.